Moments like these, you have no choice. You let your nostrils do the navigating.

It takes a block and a half to track it to the source. I’m in the part of Mission Beach where all those cute alleys sneak away into their own little worlds, with people’s gardens and patios peeping out from among the trees. Makes you long to live here.

Then, just beyond the corner with Pismo Court. I smell that aroma flooding out of a dark-green stucco place called Rosaria Pizza. Italian-looking joint, with a little patio outside at the corner of the next alley. Super-cozy, with a flaming fire ring.

“Been here a long time, this place,” says this guy, Gerald. He’s leaning against a giant American flag painted on the stucco wall of the building next to Rosaria’s. “At least 20 years. Heck, I remember Nam when he was a little boy, hanging around his mother’s knees.”

Nam

Gerald says Nam is the guy who runs Rosaria now. He ripped out his mom’s woody, folksy interior and made it all modern inside.

Main thing for me, though, is that as you go in, you’re enveloped by the aroma. Aaah…

There’s a lighter green on the walls inside, with shocking red plastic chairs, a checkered gray-black floor, and gray Formica tables. The center counter-divider is tall, with glass rising even taller. Guess that’s to stop people’s sneezes from landing where they’re kneading the dough.

A kinda frantic electronic music plays as a guy and a gal work, flattening dough. Foreign students chat as they cluster ’round the delivery section of the counter, waiting for their pizza orders. I head for the order line at the back.

Big red-and-yellow wall menu lists “Rosaria’s Origino Pizza” options. They go from $15 for a 12-inch pizza, to $23 for an 18-inch. Or you can get a slice for $2.50.

“The only thing we don’t do slices of is Nam’s Pizza,” says Nam. He’s the fast-moving Vietnamese-American guy preparing a pizza. “Everything’s fresh. It should be eaten right then, and not left to hang around in a warming display.”

Matthew, mom Tammy, Eric

Have to say, most of the pizza options look like down-the-line Italian standards. Nam’s mom opened this place in 1980, but Nam says that since he took over three years ago, he’s been working on fusion recipes for dishes that give a hint of Vietnam.

“I wanted to bring some of my family’s culture to pizzas, so I invented ‘Nam’s Pizza.’ But we’re already out of today’s ingredients.” That would be Vietnamese sweet-and-spicy sauce, Vietnamese BBQ pork, Vietnamese sausage, red onions, and fresh cilantro. Lord, just when my taste buds were getting all excited.

“It took me a year to get the recipe right,” Nam says. “Bacon with the Vietnamese sausage, but also something sweet and spicy. And Sriracha sauce, too.”

I check for sandwiches — they’re mostly $5–$6. Nam Dip looks the most Vietnamese. It comes with “Vietnamese BBQ pork, red onions, cilantro, and a side of au jus.”

“It’s a bit like the flavor of Vietnamese pho,” says Nam. “But it’s no way the same as the Nam Pizza.”

In the end, I head for the pasta section. Spaghetti’s $6.50, but I choose the eggplant parmigiana ($8.50). It arrives with a polystyrene box of salad that has the blue cheese dressing I asked for on it. The spaghetti has meat sauce (or you can have marinara). You get two pieces of toasted garlic bread.

Aaah…that’s what I was whiffing: garlic bread. That and the pepperoni smells coming out of the ovens.

It’s very hot, delish, totally Italian. The closed-circuit TV screen is showing pics of Nam’s mom. She made it out of Saigon, back in the day, then set this place up, says Nam, along with his dad, through sheer guts and cheek. And not Vietnamese food, but Italian. This is where Nam grew up, right in here.

While I’m chomping away at my eggplant masterpiece (lots of cheese!), a guy named Chris comes in and orders a $2.50 slice of green pepper and mushroom pizza.

“I’ve become vegetarian,” he says. “It cuts your cholesterol. And blood pressure. It was my dad’s idea, for him and me. I have so much more energy.”

Gerald at the flag wall

He says he’s only been in town, like, 30 minutes. “I live in Denver, Colorado. But whenever I visit I always come in here first thing. We have a little place like this that I go to in Denver.”

Lady waiting in line nods. Tammy. She grew up in this neighborhood, roller-skating into Nam’s mom’s place and ordering $1 slices of pizza with pepperoni and sausage. “We loved it,” she says. “Now we live in Texas. We’re just in for vacation this week, and we’ve been in six times for subs.”

Tammy has her two sons, Matthew (16) and Eric (10), with her. Of course, what with Nam’s radical modernization, everything’s changed since Tammy’s childhood. “I liked it better then,” she confesses. “Rose’s whole family was behind the counter, working. Now with that high divider…”

She takes a breath.

“So, it isn’t 1985 anymore. But this place is still great. I take one bite into Rosaria’s super-spicy sub [with ham, salami, spicy sausage, pepperoni, cheese, jalapeños, and red pepper flakes, $6], and — because it has the jalapeños —I say to my boys, ‘Now that’s a California sub.’”